Transcript REPRODUKSI - All About Fisheries Theory

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Gonad : ♀ ovarium : menghasilkan sel telur
♂ testes
: menghasilkan sperma
Proses pematangan telur berupa perubahan struktur,
kedudukan, sitoplasma, dan mencakup kematangan
fungsi dan fisiologis.
Sitoplasma akan menjadi tempat cadangan makanan :
kuning telur (egg yolk) dan butiran minyak (oil
globule)
Chorion : lapisan pembungkus telur paling luar
Pada chorion terdapat lubang sempit sbg pintu
masuk spermatozoa ke dalam telur, disebut
micropyle
Spermatozoa masuk hanya kepalanya (inti) saja
Setelah itu micropyle menutup untuk menghalangi
masuknya sperma lain.
Setelah telur dilepas ke dalam air dan dibuahi,
chorion akan mengeras untuk melindungi embrio
yang masih sangat sensitif
Fig.4.General pattern of development of sexual products in fishes
Perkembangan telur melalui beberapa tahap, a.l: (contoh pada
ikan Mas)
Stage I: The primitive egg cells (ovogonium or archovogonium)
are very small, their size being hardly bigger than that of other
cells (8–12 microns). They multiply by normal mitosis.
Stage II: The egg cells grow to a size of 12–20 microns, and a
follicle begins forming around each egg cell. The follicle,
whose function is to nurture and protect the developing egg,
eventually becomes a double layer of cells.
Stage III: During this stage, the egg cell grows significantly
larger to attain a size of 40–200 microns and becomes
enclosed by the follicle.
These first three stages mark the period prior to the
accumulation of nutrients in the developing eggs.
Stage IV: During this stage the production and accumulation of
the yolk begins; this is a process known as vitellogenesis. The
egg continues to grow to a size of 200–350 microns with the
accumulation of drops of lipoid materials in its cytoplasm.
Stage V: This marks the second phase of vitellogenesis. The
cytoplasm is now full of lipoid drops and yolk production
begins. The egg size reaches 350–500 microns.
Stage VI: This is the third phase of vitellogenesis, during which
the yolk plates push the lipoid drops toward the edge of the
cell where two rings begin forming. The nucleoli, which take
part in protein synthesis and the accumulation of nutrients are
seen adhering to the membrane of the nucleus. The size of the
egg is now 600–900 microns.
Stage VII: The process of vitellogenesis is completed during this
stage and the egg attains a size of 900–1 000 microns. When
the yolk accumulation ends, the nucleoli withdraw into the
centre of the nucleus. The micropyle (a small opening on the
egg shell) develops during this stage.
Stages IV, V, VI, and VII are the stages of vitellogenesis,
when yolk is synthesized and accumulated in the egg cell.
The egg is now materially ready. To reach this stage of
development, the female fish needs a lot of protein in its
food and a favourable temperature range.
On the completion of stage VII, the egg may remain as such
for several months without any change, and this forms the
“dormant” or “resting” phase.
This resting or dormant phase will either end in ovulation if
favourable conditions occur, or in follicular putrefaction
and resorption in the absence of such conditions (Figure
6).
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Figure 6.The fate of developing eggs
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Figure 7 The course of natural spawning
Figure 7 The course of natural spawning
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Figure 7 The course of natural spawning
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Figure 7 The course of natural spawning
Perkembangan Embrio Ikan
 Cleavage : pembelahan zigot sec cepat menjadi unit
sel yg lebih kecil
 Blastulasi : proses yg menghasilkan blastula, yaitu
campuran sel-sel blastoderm yang membentuk
rongga penuh cairan sebagai blastocoel.
 Gastrulasi : proses pembelahan bakal organ yang
sudah terbentuk pd saat blastulasi.
 Organogenesis : proses pembentukan berbagai organ
tubuh.
Berbagai macam organ terbentuk dari beberapa bakal
organ yang terbentuk saat gastrulasi.
-Usus, rongga kupffer, subnotochord rod : dari
endoderm
-Notochord,jantung,ginjal,gonad,sirip dada : dari
mesoderm
-Insang, linea literalis serta lipatan-lipatan sirip : dari
ektoderm
Optimal temperature of
incubation, °C
Number of days or hours
Day-grade
Common carp (Cyprinus carpio)
20–22
3.5–4 days
60–70
Pike-perch (Stizostedion lucioperca)
10–15
7–11 days
100–110
Pike (Esox lucius)
8–15
8–12 days
120
European catfish (Silurus glanis)
22–25
2.5–3 days
50–60
Tench (Tinca tinca)
22–25
3 days
60–70
Grass carp (Ctenopharyngodon idella)
22–25
1–1.5 days
24–30
Silver carp (Hypophthalmichthys molitrix)
22–25
1–1.5 days
24–30
Bighead carp (Aristichthys nobilis)
23–26
1–1.5 days
26–30
Rohu (Labeo rohita)
24–30
14–20 hours
20–22
Catla (Catla catla)
24–30
14–20 hours
20–22
Asian catfish (Pangasius sutchi)
28–29
23–25 hours
?
Clarias macrocephalus
26–30
18–20 hours
?
28
44–48 hours
?
Channel catfish (Ictalurus punctatus)
24–30
14–20 hours
20–22
Grey mullet (Mugil cephalus)
20–22
50–60 hours
?
Coporo (Prochilodus mariae)
25–26
17–18 hours
18–20
Sapoara falsa (Curimata sp.)
25–26
15–16 hours
16–18
Cachama (Colossoma oculus)
25–26
18–19 hours
?
Name of fish
Giant gourami (Osphronemus goramy)